Space-filling devices are useful for filling or occupying void regions within the human body. One example of a space-filling device is a medical implant that is implanted in a stomach of a patient to suppress the patient's appetite. Feelings of hunger can be affected by the degree to which the stomach is filled, where feelings of hunger may be related to an amount of available or empty space within the stomach. For example, a person's appetite may be relatively low when empty space within the stomach is relatively small or minimized. By contrast, the person may have an increased appetite when empty space within the stomach is relatively larger. Increased appetite or feelings of hunger can lead to increased food consumption, which over time can lead to weight gain for the person. By contrast, decreased appetite can lead to decreased food consumption, which over time can lead to weight loss for the person. Thus, weight loss may be promoted by reducing or occupying a volume of void space in the stomach to decrease appetite. Other strategies for reducing the stomach volume include placing a gastric band on the stomach, and restructuring the gastrointestinal tract with a gastric bypass.
Void regions within the human body can also contribute to pathologies and undesirable physiological states. For example, a thrombus in a void region of a left atrial appendage (LAA) can be a contributor to strokes. For example, during abnormal cardiac cycles (e.g., cardiac cycles characterized by arrhythmias such as atrial fibrillation), the LAA may fail to sufficiently contract, which can allow blood to stagnate within the LAA. Stagnant blood within the LAA is susceptible to coagulation and forming a thrombus, which can dislodge from the LAA and ultimately result in an embolic stroke. In some instances, thrombus formation in the LAA can be minimized by occluding the LAA with an occlusion device that is placed within the LAA and that fills the cavity of the LAA, or with an occlusion device that is placed across the ostium of the LAA (the opening between the left atrium and the LAA) to seal the LAA.
Aneurysms provide another example of a void region that can be associated with undesirable physiological effects. Aneurysms often occur when part of a blood vessel or cardiac chamber swells and defines a cavity, either because of damage to, or weakness of, tissue in the area of the aneurysm. Left untreated, pressure within a cavity of the aneurysm may cause the aneurysm to rupture, which can lead to a hemorrhagic stroke. In some instances, aneurysms may be treated by clipping a neck region of the aneurysm to close off the cavity of the aneurysm, by filling the cavity of the aneurysm with a material to block the cavity, or by filling the cavity of the aneurysm with a material that eliminates the aneurysm by initiating a clotting reaction within the cavity of the aneurysm.